MMF - Money Market Fund. A mutual fund often used because it can be easily converted to cash.

MAGI - modified adjusted gross income Adjusted Gross Income with certain items adjusted; exactly what is adjusted depends on the specific tax rule, such as Roth IRA conversions and IRA deductions not affecting IRA eligibility.

MCS -Monte Carlo Simulation. A problem solving technique using multiple trial runs, called simulations, which varies numbers within statistical constraints. The solution will be a statistical distribution.